From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: MD RAID Bug 7/15/12 Date: Tue, 2 Oct 2012 12:25:52 +1000 Message-ID: <20121002122552.7ba6fbb6@notabene.brown> References: <022FFCA9-5D0E-41DB-9617-202C6FAADD06@rightthisminute.com> <20121001130242.745b7ca3@notabene.brown> <42BA87F6-C5A3-4321-A4C7-0DCF0A9DF79D@rightthisminute.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/U2kY0e2lJjKDSpiz15M5Ipt"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Mark Munoz Cc: "linux-raid@vger.kernel.org" List-Id: linux-raid.ids --Sig_/U2kY0e2lJjKDSpiz15M5Ipt Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Mon, 1 Oct 2012 18:51:09 -0700 Mark Munoz wrote: > Neil, >=20 > Thank you again so much for taking time out of your day to personally hel= p me it really means a lot. I have ran the command and have successfully r= ecreated my md1 Now however md2 will not assemble. I get this error. >=20 > sudo mdadm --assemble --force /dev/md2 /dev/md0 /dev/md1 > mdadm: superblock on /dev/md1 doesn't match others - assembly aborted >=20 > Would I be correct in thinking that I just need to recreate md2 now as we= ll? Maybe, but probably not. I would think it more likely that md1 wasn't created quite right - otherwise it should have the right metadata. What does: mdadm -E /dev/md1 display now? How does that compare with "mdadm -E /dev/md0" ? What about mdadm -E /dev/sdaf (or any other device in md1)? How does that compare to what was displayed previously? NeilBrown >=20 > I assume with this command? >=20 > sudo mdadm --create --assume-clean /dev/md2 --level=3D0 --chunk=3D64 --me= tadata=3D1.2 --raid-devices=3D2 /dev/md0 /dev/md1 >=20 > Mark Munoz >=20 > On Oct 1, 2012, at 2:00 PM, Mark Munoz w= rote: > >=20 > >> On Sat, 29 Sep 2012 17:12:40 -0700 Mark Munoz > >> wrote: > >>=20 > >>> Hi I appear to have been affected by the bug you found on 7/15/12. T= he data I have on this array is really important and I want to make sure I = get this correct before I actually make changes. > >>>=20 > >>> Configuration: > >>> md0 is a RAID 6 volume with 24 devices and 1 spare. It is working fi= ne and was unaffected. > >>> md1 is a RAID 6 volume with 19 devices and 1 spare. It was affected.= All the drives show as unknown raid level and 0 devices. With the except= ion of device 5. It has all the information. > >>>=20 > >>> Here is the output from that drive: > >>>=20 > >>> serveradmin@hulk:/etc/mdadm$ sudo mdadm --examine /dev/sdaf > >>> /dev/sdaf: > >>> Magic : a92b4efc > >>> Version : 1.2 > >>> Feature Map : 0x0 > >>> Array UUID : 6afb3306:144cec30:1b2d1a19:3a56f0d3 > >>> Name : hulk:1 (local to host hulk) > >>> Creation Time : Wed Aug 15 16:25:30 2012 > >>> Raid Level : raid6 > >>> Raid Devices : 19 > >>>=20 > >>> Avail Dev Size : 5860531120 (2794.52 GiB 3000.59 GB) > >>> Array Size : 99629024416 (47506.82 GiB 51010.06 GB) > >>> Used Dev Size : 5860530848 (2794.52 GiB 3000.59 GB) > >>> Data Offset : 2048 sectors > >>> Super Offset : 8 sectors > >>> State : clean > >>> Device UUID : 205dfd9f:9be2b9ca:1f775974:fb1b742c > >>>=20 > >>> Update Time : Sat Sep 29 12:22:51 2012 > >>> Checksum : 9f164d8e - correct > >>> Events : 38 > >>>=20 > >>> Layout : left-symmetric > >>> Chunk Size : 4K > >>>=20 > >>> Device Role : Active device 5 > >>> Array State : AAAAAAAAAAAAAAAAAAA ('A' =3D=3D active, '.' =3D=3D mis= sing) > >>>=20 > >>> Now I also have md2 which is a striped RAID of both md0 and md1. > >>>=20 > >>> When I type: > >>>=20 > >>> sudo mdadm --create --assume-clean /dev/md1 --level=3D6 --chunk=3D4 -= -metadata=3D1.2 --raid-devices=3D19 /dev/sdaa /dev/sdab /dev/sdac /dev/sdad= /dev/sdae /dev/sdaf /dev/sdag /dev/sdah /dev/sdai /dev/sdaj /dev/sdak /dev= /sdal /dev/sdam /dev/sdan /dev/sdao /dev/sdap /dev/sdaq /dev/sdar /dev/sdas > >>>=20 > >>> the following error for each device. > >>>=20 > >>> mdadm: /dev/sdaa appears to be part of a raid array: > >>> level=3D-unknown- devices=3D0 ctime=3DWed Aug 15 16:25:30 2012 > >>> mdadm: partition table exists on /dev/sdaa but will be lost or > >>> meaningless after creating array > >>>=20 > >>> I want to make sure by running this above command that I won't affect= any of the data of md2 when I assemble that array after creating md1. Any= help on this issue would be greatly appreciated. I would normally just DD= copies but as you can see I would have to buy 19 more 3TB hard drives as w= ell as the time to DD each drive. It is a production server and that kind = of down time would really rather be avoided. =20 > >>=20 > >> Running this command will only overwrite the 4K of metadata, 4K from t= he > >> start of the devices. It will not write anything else to any device. > >>=20 > >> so yes, it is safe. > >>=20 > >> NeilBrown > >>=20 > >>=20 > >>=20 > >>>=20 > >>> Thank you so much for your time. > >>>=20 > >>> Mark Munoz > >>> 623.523.3201-- > >>> To unsubscribe from this list: send the line "unsubscribe linux-raid"= in > >>> the body of a message to majordomo@vger.kernel.org > >>> More majordomo info at http://vger.kernel.org/majordomo-info.html > >>=20 > >=20 >=20 > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --Sig_/U2kY0e2lJjKDSpiz15M5Ipt Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBUGpQsDnsnt1WYoG5AQK80g//ZlZe0xCat4NHnrbhjTycyIR59aqgXrkk cvNC591jdiha5eQ2/tIeat6VhnQurX68a4z1OqhZx+FiJBBG2QcYWOl+ECs8u0SA 8VBYAJ+qUZbmjxn5WVIoHGAbL+valXDz0aVztfYcvCMuB0+HXtfOHz/4ai0cJlee NvbCWjrIpW6P4fNh/jx26jRJDncBLF3pAXzEZTljO9tAUmGWseRoAfLPlnvsi74h udEHebBx29o1AlWjHzmDALgQwvpUMGA+v/YJ42TPKacFFJkYl6dOYH2/OUyxvdzV vYBOfoKLWRHjSEsjFfONj/1DbQINgB+TNpIS3GkUTne3dpS59SgOc2gI5gnFyiL1 hKNb8jLCDAWiJaZyesWJqL+Ies/6GOqBtbmICPj985Yc+b0gRFXXZBuU93/Yn+OI Lz8PP3dpeupAw+lWM21M7WT34UwyoyL09sZC4bhRK7Bet+jJXqlJIU/XlT8wUMO/ /uQ2t5cDTNTsvwXSbQr+fCVMdFJshqkSBT7GzbpnGo4AVjnKeqlgc+PV9hplmVKK 2frJRK5O1v0aLdStiQnj39Ipkf4UGrBoSpRElSZh2pGWPhE2Doq+/7s8Sw70Z1mM GTOLnAfy+K4bL6SCdbqLozP9pDxDCDeXlgK208NyLjVRZP7rf6/WokJLbRkt3yrF tygKcBOdr68= =cDVb -----END PGP SIGNATURE----- --Sig_/U2kY0e2lJjKDSpiz15M5Ipt--